Abstract: A piston ring assembly has an expander spring of sheet material bent into an annular configuration. The expander spring has a circumferential series of radially oriented tongues and each tongue has an approximately axially bent leg. The tongues and legs are defined by stamped-out slots provided in the expander spring in an alternatingly radially inwardly and radially outwardly oriented circumferential series. The expander spring has stamping burrs bounding the slots. The piston ring assembly further has two laminar oil scraper rings arranged generally concentrically with respect to the expander spring. The laminar oil scraper rings are axially supported by the tongues and are radially supported by the legs. The burrs are situated such that they are submitted solely to compression forces derived from bending stresses generated as a result of bending the spring into the annular configuration.

Abstract: Oil scraping piston ring of profiled steel having punched-in oil vent holes. To keep at a minimum the bulging at the holes developed during coiling, the oil vent holes are given an elliptical or rhombic outline.

Abstract: A piston-and-ring assembly includes a generally cylindrical piston, a circumferential groove provided in the piston and having a bottom and two radial flanks forming opposite sides of the groove; and an expander spring ring accommodated in the groove and including a plurality of generally radially extending tongues arranged in a circumferential series. Each tongue has, at a radially inward end, a leg portion extending at a first angle other than zero to the respective tongue from which it extends. An oil scraper annular lamina is situated in the groove and is supported axially by the tongues and is abutted radially by the leg portions. An extension forms part of each leg portion and is oriented thereto at an inclination. Each extension has a length which extends substantially from one of the flanks to the other.

Abstract: An oil scraper piston ring assembly includes an oil scraper ring received in a piston groove and being in circular contact with a first side wall of the groove; and a spring ring received in the groove between the oil scraper ring and a second side wall of the groove. The spring ring has circumferentially distributed resilient tongues oriented alternatingly radially inwardly and radially outwardly. The spring ring has a radially outer circular part situated axially adjacent the oil scraper ring and a radially inner circular part bent with respect to the radially outer circular part and extending at least partially radially adjacent an inner periphery of the oil scraper ring. The oil scraper ring is a steel band ring of relatively small axial height, the spring ring is a resilient band ring also of relatively small axial height, and the oil scraper ring and the spring ring have approximately identical thicknesses of material.

Abstract: A piston ring assembly has a ring-shaped expander spring composed of an annular body defining an axial direction and presenting a circumferential main bending region and a plurality of resilient tongues extending radially outwardly from the main bending region and adjoined, adjacent the main bending region, by generally axially extending parts of the annular body. The assembly further has a lamina lying, at least in part, on the tongues and is radially supported by the axially extending parts. The main bending region is disposed radially inwardly of the lamina.